“What you eat” alone does not determine a person’s size. Here are some factors that matter, and they aren’t all of them.
Body Type
What might your natural body be? Willowy and thin? Muscular and medium? Strong and hearty or round? Think about the distinct body type, meaning shapes and characteristics people are born with. Some of us cannot muscle up, others cannot not muscle up. Some are thin no matter what they put in their bellies, and some would have to become starved (or intensely ill) to encroach upon being classified as “slim.” Some have combinations (upper/lower bodies) of these mentioned types that are referred to as ectomorph, endomorph, and mesomorph.
Finances
Socioeconomic status plays into the role of size. There was a recent study about adolescents pairing “healthy” eating with “moral” eating or an attitude of “better than.” Realistically, financial privilege allows the option of “healthy” (I like to call it “nutrient-packed, more colorful eating”) eating. Whereas, limited funds don’t allow as much choice when at the grocery store.
If you have any question about the above I invite you to do an experiment: Price out produce at your local market vs. more calorie dense, less “healthy” foods. Maybe check the protein of fresh salmon vs. frozen chicken tenders, the snack of fresh grapes vs. family sized chips, or organic anything vs. not organic anything. Pick whatever you want to compare.
Finances certainly affect food choices.
Your Brain
The brain and how it is wired affects our size. A recent study by Vainik and colleagues (2018) highlighted that it seems that gene vulnerability to BMI is in the brain. This means that we come into the world with much about our size preset—and that does not mean just size; it can include behaviors, too.
Of course, neuroplasticity exists and has been proven to allow for change in the brain’s wiring. However, when we consider our basic genes, there is a certain amount of our biological-destiny we cannot change.
Here’s what I mean. If my genetics determine that I’m going to be just under five foot but I wish I was 5’11”, there is not much I can do. And vice versa. If I get the combination to give me red hair, I can’t really change this from the inside, no matter what I eat or dyes I drink. Same with skin tone. Any changes are from the outside and usually temporary. Suntans fade. Nowadays, other skin color changes may be medically-induced and more permanent. But my point is this: Genes in the brain and body are powerful contributing determinants of each of our sizes, like our natural hair color and skin tone.
So…
If we each had or wanted to explain/understand our individual size and how we got here, these first three elements—natural body type, socioeconomic status, and brain structure/genes—are only the beginning in a long ingredient list. It would be a complex and multi-factored explanation.
Most Importantly
“What you eat” is a too-simple and punishing of an explanation to tell anyone—especially yourself.
References
Priya Fielding-Singh. (2019). You’re worth what you eat: Adolescent beliefs about healthy eating, morality and socioeconomic status. Social Science & Medicine, 220, 41-48. https://doi.org/10.1016/j.socscimed.2018.10.022
Vainik, U., Baker, T. E., Dadar, M., Zeighami, Y., Michaud, A., Zhang, Y., José C., . . . Dagher, A. (2018). Neurobehavioral correlates of obesity are largely heritable. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.1718206115
